Long-Term Outlook Calls For Cool Summer

Hopefully the intensive wet trend will give way sometime in early May. However, Ken Scheeringa expects temperatures will stay on the cool side throughout the spring. He also believes farmers may have to dodge rain showers to get crops in the ground even once the weather pattern settles down and soils are dry enough to begin working again.

Scheeringa is the assistant state climatologist for Indiana, based at Purdue University. Recently, Indiana Prairie Farmer asked him to study long-term maps and provide his interpretation of what farmers could expect for the growing season in Indiana extending through the majority of summer. Much of the information for long-term weather forecasts is assembled by the National Weather Service.

"They're talking about a cooler than normal summer across this part of the country," Scheeringa explains. "Part of that is based upon the idea that we're starting with wet, saturated soils and that will tend to hold temperatures down until things dry off.

"As far a precipitation goes, there is no clear signal for that part of the Midwest at the moment. Officially, the National Weather Service long-term forecast maps place it at normal over Indiana. That means there is an equal chance of being on the dry side, on the wet side or truly normal."

The basic forcing factor playing into this is the demise of the La Nina during the spring, he adds. La Nina is the cool phase of the El Nino/La Nina cycle. It's all about sea surface temperatures way off shore in the tropical Pacific Ocean. When they're below normal, it's a la Nina. They cycles are irregular, and typically take three to five years to complete.

Surface temperatures far out in the ocean affect atmospheric pressure, which affects air circulation patterns aloft. Weather patterns across the entire world are determined by these cycles. However, other factors can affect the cycles, such as the anticipated effect of cooler weather due to wet soils in the Midwest this spring.

So what happened to the dry summer once talked about? While it can't be ruled out, Scheeringa says there is no indication now that it will develop. "They are calling for dry, hot conditions in the southeastern U.S.," he says. "However, the thinking now is that the hot, dry weather will stay far enough south of Indiana that it won't creep into the Hoosier state and affect weather patterns here."